Field of the Invention
The present invention relates to a letterpress printing press wherein one or more stacked sheets, which each have a surface which changes color when pressure is applied (so-called active paper) or which each come into contact with an ink film support comprising a layer, which rubs off under the influence of pressure (dye band, carbon paper), are pressed against a letter press form by the printing progress of at least one cylindrical roller element in a combined pressure-applying and rolling movement.
In the printing industry, the term printing progress refers to the rolling movement of the impression cylinder on the printing form.
In the known machines of this type, the cylindrical roller is mounted in journal bearings which, to permit printing progress, are displaceably guided, are equipped with a sliding drive system, are capable of bearing a compressive load for the application of pressure, and can be raised from the printing form in order to insert and remove the sheet or sheets. Complicated mechanisms having relatively large dimensions in the direction in which pressure is exerted, were required for this purpose.